The invention relates to a charged particle system, such as a multi beam lithography system. Charged particle systems, such as (multi) electron beam systems, are being developed for high throughput maskless lithography systems, (multi) electron beam microscopy and (multi) electron beam induced deposition devices.
Many of these charged particle systems have complex modules arranged for specific tasks. In order to facilitate maintenance of these modules, a malfunctioning module can be removed from the charged particle system and can be replaced by a (new or repaired) functioning module.
However, some charge particle systems, especially some maskless lithography systems, use a large number of charged particle beams for processing a target (or wafer), for example more than 10.000. If these charged particle beams pass through several modules, the alignment of these modules with respect to each other after replacement of one of the modules becomes difficult because of the required accuracy of the alignment. This is especially the case when a typical beam spot of the charged particle beam and a typical distance between two neighbouring beam is in the range of micrometers, or below.
A complex and therefore time consuming alignment procedure after the replacement of modules would extend the downtime of a system more than is desirable.
When building the lithography system or the microscopy system, the various functional modules or elements are mounted in a frame. Although the accurate alignment of the functional elements with respect to each other provides a challenge on its own, this alignment can be impervious to thermal expansion or contraction of the functional elements and/or the frame. It may therefore be a problem to arrange modules in a stack with high accuracy and preferably wherein the alignment of the functional elements is at least substantially independent from temperature variations.
It is an object of the present invention to provide a solution, at least in part, for at least one of the above identified problems.